柑橘CsNCED3-2的克隆及其响应溃疡病菌侵染的表达分析

Cloning and Expression Analysis of CsNCED3-2 in Responding to Citrus Canker Disease

柑橘溃疡病是世界柑橘的一种重要病害,对柑橘产业造成严重的经济损失。对柑橘中9–顺式–环氧类胡萝卜素双加氧酶(NCED)基因家族进行注释,并克隆出受柑橘溃疡病菌诱导表达的CsNCED3-2,确定了其表达模式。从柑橘全基因组公共数据库共注释出14个NCED基因家族成员,根据系统发育树和功能结构域将其分为4个亚类;CsNCED3-2其序列全长2377 bp,开放阅读框1830 bp,编码609个氨基酸,属于RPE65超家族成员和类胡萝卜素双加氧酶家族成员,是非分泌性蛋白;在‘晚锦橙’和‘金弹’叶片注射溃疡病菌后的各个时间点,‘晚锦橙’叶片中CsNCED3-2的相对表达量总体高于‘金弹’,并且两品种的相对表达变化呈相反趋势;与茎、叶和种子相比,CsNCED3-2在两品种果皮中表达量较高;两品种的CsN CED3-2上游启动子均含有参与植物激素和逆境应答相关的顺式作用元件ABRE(脱落酸响应)、TCA-element(水杨酸响应)、MYC/MYB(干旱响应)等,但数量和类型存在差异。

Citrus canker is an important disease of citrus in the world and causes severe economic losses to the citrus industry.In this study,the 9-cis-epoxycarotenoid dioxygenase gene(NCED)family of Citrus sinensis were annotated,and the citrus canker related CsNCED3-2 was cloned and its expression pattern was analyzed.A total of 14 NCED family members were annotated from the public genomic databases of C.sinensis.These 14 NCED family members can be divided into 4 subclasses based on the phylogenetic tree and functional domain.The full-length of CsNCED3-2 is 2377 bp with a 1830 bp open reading frame which codes a protein containing 609 amino acids.The CsNCED3-2 gene belongs to the members of the RPE65 superfamily and the carotenoid dioxygenase family,and it is a non-secretory protein.After inoculated with Xanthomonas citri subsp.citri(Xcc),the expression of CsNCED3-2 in Jindan(Fortunella crassifolia Swingle)was always higher than that in Wanjincheng orang(eCitrus sinensis Osbeck)at different time points,and the variation trends of expression in the two varieties were opposite.The expression of CsNCED3-2 in the peel of Wanjincheng Orange and Jindan were higher than that in the stem,leaf and seed.The CsNCED3-2 promoters of Wanjincheng Orange and Jindan contain multiple cis-acting elements involved in plant adversity and hormone responses,such as ABRE(abscisic acid response),TCA-element(salicylic acid response),MYC/MYB(drought response)and so on,but there are differences in their number and type.